TransLink issued a statement saying the fire had caused delays to the Blue Mountains Line.

“Delays due to a fire on a train at Lawson. Bus companies are being contacted to operate a replacement service between Springwood and Katoomba,” a TransLink spokesman said.

Train passenger Timothy Wells posted a video of a small fire on the roof of the train on social media and thanked emergency crews for their assistance.

“So everyone was safe and evacuated the police were fantastic,” he said.

“It was controlled and beautifully managed. Go the local emergency survives (Sic) and Firies”

It is not clear what caused the fire at this stage but fire investigators have started an investigation.